Fittings are used to connect two objects, such as, for example, a tube and a device that facilitates fluid communication with the tube. One example of such a device is a valve. Fittings may also be utilized to cap or plug an opening or aperture. Additionally, fittings must maintain a seal against leakage while meeting various design criteria relating to, for example, pressure, temperature, and vibration.
It may be advantageous to provide for early detection of conditions that could cause a leak or the incipient leak conditions for the purpose of instituting fail-safe operations and/or preventative maintenance.
Presently, connections between fittings may be susceptible to leakage. Leakage may cause hazardous conditions due to the escape of oxidants, odorants, pharmaceutical fluids, fuels, poisonous substances or otherwise objectionable or undesirable substances. Leakage may cause loss of valuable substances or the interruption of processes involving the accurate and adequate delivery of certain substances. In addition to degradation of an O-ring or gasket forming a seal between the fittings, leakage may result from mechanical loosening of the connection. One typical cause of loosening may be thermal cycling or vibration of a system comprising the fittings.